A door frame that forms a window frame of a vehicle door includes a frame portion, which serves as a framework of the door frame, and a weather strip, which is secured to the frame portion. The weather strip seals the space between the frame portion and a vehicle body.
Patent document 1 describes a door frame, as shown in FIG. 5, including a frame portion 90 formed by joining an inner sash 91 and an outer sash 92. The inner sash 91 includes a base-like coupling portion 93, and a coupling hole 93a extends through the coupling portion 93. A weather strip 96 includes a coupling hole 97 facing toward the coupling hole 93a. An engagement portion 99a of a clip 99 is inserted through the coupling hole 97 of the weather strip 96 and the coupling hole 93a to fasten the frame portion 90 and the weather strip 96.
Further, in the prior art, as shown in FIGS. 6(a) to 6(c), a door frame that joins a resin garnish 100, in lieu of the outer sash 92, to the inner sash 91 (frame portion) has been proposed. The resin garnish 100 forms a design surface at the outer side of the vehicle. A dedicated clip 101 secured to the garnish 100 is inserted into a coupling hole 102, which is formed in the coupling portion 93 separately from the coupling hole 93a, to fasten the garnish 100 and the inner sash 91.
However, in this case, the clip 101 becomes necessary in addition to the clip 99. This increases the number of components. Further, as shown in FIG. 6(c), the inner sash 91 is recessed from the outer side of the vehicle by an amount corresponding to the projection length of the coupling portion 93, and the clip 101 is fixed to a garnish box 103, which projects from the garnish 100 toward the inner side of the vehicle facing the coupling portion 93. When, for example, load is applied from the outer side of the vehicle to the garnish 100, the garnish box 103 may be broken due to interference with the inner sash 91. Accordingly, the minimum thickness of the garnish box 103 and the garnish 100 has to be determined to ensure that the garnish box 103 has sufficient strength. This reduces the freedom of design.
Referring to FIG. 7, patent document 2 describes a door frame that employs an aluminum inner sash 110 (frame portion) to reduce the weight. In this case, since the bending characteristics of aluminum is generally poor, the base-like coupling portion, which may be a bent portion, is omitted from the inner sash 110. In other words, the resin garnish 116 and the inner sash 110 are joined without using a base-like coupling portion as the inner sash 110.
More specifically, the inner sash 110 includes a flat portion, which is free from bent parts and provided with an insertion hole 111. A garnish 116 includes a coupling projection 117 inserted through the insertion hole 111. A clip 119 is inserted through a coupling hole 122, which extends through the weather strip 120 and an inner insert 121, and inserted into a coupling hole 117a arranged in a front surface of the coupling projection 117 to fasten the inner sash 110 and the weather strip 120. This allows for the fastening of the inner sash 110, the weather strip 120, and the garnish 116 without increasing the number of clips even while keeping the inner sash 110 flat.